Thanks again, @photo-trail! I love your questions. I use the expensive Metabones mk IV adapter. It does the job quite well with the 70-200, but it is not native Canon speeds, also the Sony does not necessarily focus fully open like a DSLR, so it does not do as well in low light. Some annoying hunting will keep you from getting the shot. My solution is to increasingly use manual focus, as this is easier on the Sony with its EVF. I can't afford Sony glass just yet, as Im invested in Canon.